The present invention relates to a multipurpose heat pump system which may supply cold water for air conditioning in summer and hot water for air conditioning in winter, as well as hot water needed in daily life, for example, for dish washing and bathing, etc. via different circulation combinations and operations. Such heat pump system not only meets needs in different seasons, but also increases energy utilization efficiency. The heat pump system is also helpful in environmental protection.
For areas in subtropics, such as Taiwan, researches concerning air conditioning generally focus on the indoor cooling effect rather than the heat pump system for supplying heat energy. It can be found from general users in Taiwan that most heat pump systems have very low rate of use in winter, some of them are even completely shut down and the equipment is idle.
When a heat pump system is in the process of refrigerating operation, refrigerant in the form of low pressure vapor is compressed by a compressor into a high-pressure overheated vapor which is then discharged into the atmosphere by way of air cooling through a condenser and results in a greenhouse effect in surrounding environment. If heat so produced can be recovered for use in supplying hot water, not only the condensing pressure required by the condenser can be reduced, the coefficient of performance (COP) of the heat pump system can also be upgraded. Moreover, an increased energy utilization efficiency can be achieved and a negative influence of the high temperature of the discharged vapor on the environment can be reduced.
When a gas heater or an electrical heater is used to produce hot water, only a low heat energy per unit cost can be obtained while there is risk of gas poisoning or electric leakage. The safety in use of these heaters is therefore very low.